From Botanical Extracts to Functional Nanocatalysts: A Critical Review of Green Synthesis and Photocatalytic Performance

Plant extract mediated production of environmentally benign nanomaterial is growing demand and an emerging branch of green nanotechnology. Utilization of natural phytochemicals as reducing, stabilizing, and capping agents provides an eco-friendly route for nanoparticle synthesis. These secondary metabolites reduces chemical hazards while producing stable nanostructures which are suitable for catalytic and other functional applications This paper provides a comprehensive overview of recent advances in the biosynthesis of various nanomaterials such as metal, metal oxide, and composite, hetero-junction nanomaterials using diverse plant extracts, emphasizing the phytochemical mechanisms governing nucleation, growth, morphology control, and functionalization. Phyto-synthesized nanomaterials are further employed in environmental remediation processes, including the degradation of organic pollutants, removal of heavy metals and dyes from water via photocatalysis and soil, and antimicrobial treatments, owing to their enhanced reactivity, high surface area with great stability and eco-friendly synthesis route. The review concludes with emerging trends and future research directions aimed at enhancing reproducibility, exploring underutilized plant resources, integrating hybrid green synthesis strategies, and advancing the practical deployment of phytogenic nanomaterials in photocatalytic technologies.